Carburetor



Patented May 12, 1942 osiuiunrz'roav` l Warren C. Conover, Waukegan, lll.. assignor toV Outboard, Marine a; Manufacturing Companyf Waukegan, llla corporation of Delaware Aopiiooaon Anglia' 1, 194e, serial No. 349,913.' j

" 9 claims. (ci. 12a-119) This .invention :relates to improvements in carburetors with particular reference to the. type of arburetor in which carbureted air is supplied to adual manifold'arrangement.-

It is the primary objectof kthe invention to provide novel andimproved means whereby the mixture will be uniform in each off two Amanifolds suppliedwith 'carbureted air. i Both vin four cyl cle engine practice and in two cycleenginefpractice, it is frequently desirable to employV separateV manifolds for different cylinders or-groups of cylinders. If the mixture supplied .to one manifold is richer than that Vsupplied vto anotherfor varies Vvin quantity, 'the cylinders will lire unevenly. Whereeach manifold is supplied-with ya. separate VVc'a'rl iurei'.or,it is almost impossible to secure unlforxnity of mixture. The sameistruefwherethe output of; a single carburetor is divided,v after carburetiombetweenthemanifolds.

By the present invention, I seek to provide a Yvery simple,V inexpensive and direct way of 'equalizing the carburetion Vas between a plurality of manifolds supplied by asingle jet. It is a further object of the invention to provide an arrangement whereby portions of the manifolds are formed in a throttle valve structure, preferably directly associated with the jet.

Other objects of the invention will be apparent 'from the following diso1osure.

In the drawing: e Fig. 1 is a view partially in plan and partiallyin horizontal section'sliowinga carburetor embodying the invention.

Fig. 2 is a view partially in vside elevation and partially in vertical section through ,the carburetor. and associated structure shown in Fig. l.

Like parts are identified by the same reference characters throughout the several views. By way of illustration;r my improved carburetor is shown applied to a dual crank case rotary valve two cycle engine', this being one 'structure in which dual manifolding is desired. The crank shaft 3 is provided with` cranks 4 andi in the crank cases 6 and 1. The crank shaft cheeks 8 and 9 constitute rotary valves having segmental openings such as those indicated at l0 and Il for admitting to the respective crank cases combustible mixture supplied throughthe manifold passages I2'and` I3, respectively. Manifold'passage I2 turns upwardly to be controlled by valve numbered 8 while manifold passage I3 turns downwardly to be controlled by valve numbered 3. As viewed in Fig. 1,*the passages I2 and I3 in Vthe Y. crank case structure are; ll'lorizontal and;y gt

the same level.

' 1 The carbureting chamber `is provided-ina lateral extension with "the conventional oat chamber I3,fdetalls of which-ar-not shown. It has an air inlet -port atll andrisprovided at I8 with y a 4cylindrical.bearing' in whlch thethrottle valve I9 isvrotatabla The throttle valve VI Sfcomprises a generally cylindrical structure'having an air passage divided by partition '20 to4 comprise`V separatey manifolds 2lV andv 2,2 of graduallyrim. creasing cross section. 'I'hese' manifold's'- communicate Ywith .theffdivergent manifoldvpassages j Y 23 and 2 4 which lead respectively; into the'cxjankA `caseuianifold passages I2 and I3.

f The diverging manifold passage sections 23-Ik and with partition 20` 4in.theUthrottle valve, b'u'tis spaced therefrom, In the 'space 26,1'vwhichfafi4 fords communication between the separatev mani-Vv foldbranches.. is they carburetor jet 21 which projects on-a minorchordiinto the cylindrical space .in which thethrottlevalve r`otates Y This .iet is, supplied With, fuel` from "the float'clif1-l1'l'1er'` I87`; through a seriesof ports and passages 4subject to the controleof needlevalve 28. Ihecross' se'cy" tional areas of the v xrlanifold'sections 23 Vand 24 are egual. as are the cross sectional areas of I manifold sections Ilv 'and I3." The cross sectional areas of manifold branches2| and 2 2'within the throttle valvefIS are equal toeach' other,

but are preferably somewhat reduced as com.

Paid' with' iheja'res olf the extensions 2a ssd u thereof. Y

While I fiiavoA snowii`- portions `off-the manifold branches formed in a. throttle valve, I wish-'to Y .24 arespaced by a partitionZSl which isin line 1 make it clear that inthe broaderv aspectskof the j orY in some; other" portion of the carbureting chamber.y Broadly, itis onlyjim'portant thatjthe airj iscarried by'.A separate 'manifoldpassages 'whieh .communicate with-'each other Aabout the iet. In addititon'to this broadfpincipleit is,y of f course; advantageoqs'in the'interestslofcompact 55 Y since the engine disclosed is a two oyole ein'Y f ypresent invention, it'isimma'terialwhether these y 46 passage sections bef'forrned in a throttle valve poss and simplicity to inoorporii'teporiions of the f A.passagesin thesh'rottle valve'as sl i' own. The Vthrottle valve isvheldfinplace bya' -rolo- V sure 30 through which thevalve stem vprojects at- '3| to be'manually adjusted'by'fa'handlef32';

Naturally, the manner 'in which the throttlevalve 'Y vis controlled is not of importance tothe present invention.

gine, it will be understood that the mixture ldelivered to the respective crank cases 6 and 'l will be compressed therein and transferred to the respective cylinders 33 and 3|. For the purposes of the present invention, it is immaterial whether the mixture is delivered directly to the cylinder, asin four cycle engine practice, or is nrst delivered to the respective crank cases, as in the two cycle engine disclosed.

In either case, the uniformity of mixture supplied through the separate manifold passage will any other construction which .is known*- to me.

This is particularly true in the devicej as disclosed v' where the respective cylinders are drawing their mixture alternately through Ythe Y carburetor.

When mixture is being drawn into crank case 6 through manifold passage I2, no mixture is passing through manifold passage i3 to crankcase 1.

Under lthese circumstances,y it will be appar- .,ent thatfthe major portion of the airrentering manifold. passage l2 '.will comev directly thereto throughmth'e v manifold section `2|, but a, part of the air supplied tosuch passage will come to the Ypassage' through' manifold section 22* and theV ,communication aperture 26 which affords communication betweenY the passages. In Aso doing, [the Aportieri ofthe fair traversingV theby-pass openingl will' be lcarbureted and the jet 2l and needle valve,A v28 are so devised that suicient rcar- A,tamponLwiu `be supplied. to this portion of the airto satisfy 'the entire requirements of the cylinder to Vwliichthis portionjof the air is supplied. Conversely, whencylinder v3,4 randcrank case "'l are drawing airthrougli manifold 'passages I3 and'. 24, the 1inajonportion o f suchair will be Y suppliedthrough 'manifold section 22, but a portion thereofwillcross over from manifold seci tionzi through theA communication opening 26 and will be carbureted, in passing the jet 21. I

' ,Qfblieve.that'superior results vare possible if the air stream is 'divided,'as kby' partition 20, before it encounters the jet` at 21, but in any "event,

there should be some rv'definite exchange `of air from one lsideoiv the manifold system to the other across the jet. It is this fexchange which" is believed to account for thrsurprisin'g uniformity of carburetion in both branches `of the manifold system.

I claim:

s 1,. carburetor of the ,Y character described comprising the combinationV with a carbureting g, chamber, havingY separate. passages and interven- `ing partition and a cylindrical. throttle valve bearing from which said passages open,.of a jet 2. A carburetor having separate air passages opening'inl proximity to each other and 'com- Y, municating with each other ata point intermediate the length of each, a single fuel -jet nozzle disposed at saidvpoint 'of communication ina position'toV carburetat least a part lof the air entering each, and means for supplying liquidvfuel to said nozzle, variations insuction in the respective'passages being thereby adapted to draw gines having separate manifold inlets and meansV for alternately applying suction at the respective inlets, said carburetor having separate passages leading to the respective manifold inlets and y cross connected for delivery of the air stream to either-.of such inlets, and said carburetor having its main fuel jet nozzle disposed in said cross f connection in av position to be exposedto suction be surprisingly constant and more nearlyldenl' tical as between the separate manifolds than in exerted through either of the manifold inlets.

4f. A carburetor comprising a chamber having inletand outlet portions and an intermediate partition, a nozzle connected with a source of liquid fuel supply and located in line with and adjacent the inner end of said partition, and an- -other partition located between said nozzle and the chamber inlet substantially in the plane of the first mentioned partition, whereby air passing fromioneyside of thechamber to the'other maybe concentrated upon the nozzle outlet for aspirating purposes.

5. A carburetor, comprising a chamber of gaf generallytubularform and provided with inlet V`and outlet ports, ai cylindrical throttle valve transversely disposed'with-itsr` ends journaled in.r Y the side walls of the .chamber and intermediately portedgfor communication ybetween the inlet and VVoutlet portions of the chamber, a partition in the throttle Vvalve portadapted to sub-divide the air stream passingV therethrough, means for correspondingly sub-dividingfthe air stream at the carburetor outlet, and -a fuel nozzle extending Vinto the outlet end*` ofthe throttle valve portin .the plane of itsgpartitionnand spaced therefrom.

Y 6. vIn a carburetorof the bcharacter described, the combination with means providing separate outlet passages of substantially uniform cross oflike cross section with reference to each other,

section and corresponding air inlet passages also thecross sections of the respective inlet passages being reduced as compared with those of the outlet passages, said carburetor having, a mixing chamber between the inletand outlet passages permitting air flow from either inlet passage to either outlet passage, and a main fuel nozzle lated in the central portion of the mixing chamber substantiallyin a plane midway between the outlet passages, whereby air may be drawn by suction'applied to either outlet passage across the nozzle from the opposite side of the mixing chamber.

'7. A carburetor having a generally tubular air passage Vexpanded atjits inner end to cover the inlet ports ofra duplex manifold, a cylindrical throttlevvalve journaled in the walls of the passage and ported Vfor air delivery therethrough, a

Vand located in frontV of the outlet end 0f said port, Yand* a fuel nozzle extending through the wall of the passage `and projecting on a minor chord into the throttle `valve port, with its` outlet in line withthe partition, said partition being adapted to sub-divide the air stream flowing through said port, and the Vwalls of saidpassage being. formed to-provide a cross connectionV between the air streams onopposite sides of said partition, and also adaptedto concentrate upon said nozzle air flowingv through said cross connection..

8. The combination with an internalcombustion engine Y having dual inlet passages and means for applying suction alternately in the resans 3 spective passages, of a carburetor having corregines, comprising the combination of an air sup-` sponding air outlet passages of less capacity, ply tube,anoscillatory throttlevalvehavingaport cross connected in their inlet end portions to partially subdivided by a partition in line with permit delivery of air from either carburetor the tube axis, a nozzle having its outlet'l at the passage to either engine inlet passage, and 5 outlet side of the throttle valve in--line with saicl means for feeding liquid fuel into said cross conpartition and spaced therefrom, and connectio nection for supplying liquid fuel to the nozzle.

9. A carburetor for internal combustion en- WARREN C. CONOVER. n 

